The Andes Physics Tutor

Andes is an intelligent homework helper for physics. That is, it
replaces the pencil and paper that students would ordinarily use to
solve physics homework problems. Students draw diagrams, enter
equations and define variables with the same freedom that they have
when using paper. Yet, unlike a piece of paper, Andes tells
students whether their entry is correct by turning it red or green,
and Andes will give principle-based hints when asked.
Several semester-long evaluations of Andes showed that students
who did their homework on it learned significantly more
than students who did the same homework problems on paper.

Andes is intended for use in an Introductory College Physics course, a
high school physics course, or a distance learning course. It
includes over 500 problems that cover most topics in a standard
two-semester trigonometry-based physics course. It is free,
courtesy of funding from the National Science Foundation.